By Sherri Roberts, PAg, Crops Extension Specialist, Weyburn
Beneficial insects have a tremendous impact on agricultural production. They can be divided into three different categories: pollinators, predators and parasitoids. Pollinators are insects like bees, butterflies, flies and moths that pollinate flowers and in so doing they can maximize seed production. Predators have a diet that prioritizes eating insect pests while parasitoids utilize pests as part of their life cycle.
When deciding if spraying an insecticide is necessary, sweeps — counting not only the destructive insects but also the beneficial ones — should be done. Thresholds have been established for what level of destruction will be yield limiting along with what threshold will be economically viable. By counting the beneficials along with destructive insects, you may decide to let mother nature take her course.
There are countless tables available that cover the threshold levels for various pests. After reviewing them, should you decide spraying an insecticide is necessary, please read the label to learn what beneficials could be affected by your insecticide choice. Be mindful of insecticide spraying times as applications made at flowering are much more likely to have negative impacts on pollinators. If you have any questions, please contact your regional crops extension specialist or the Agricultural Knowledge Centre at 1-866-457-2377.